Steerable medical devices and other minimally invasive surgical tools are being increasingly used to perform medical procedures inside a patient's body. Steerable devices generally include an elongated sheath and one or more control cables having distal ends secured at or adjacent the distal tip of the sheath. A control knob or lever selectively tightens the control cables in order to bend the device in a desired direction. The problem with most medical device controllers is that they require two hands in order to move the distal tip of a device in more than one plane. Alternatively, in those designs where a user can move the distal tip in four directions with one hand, two hands are still required in order to advance, retract, or rotate the device. Although some robotic systems have been proposed to allow a physician to direct a distal tip of a device in any direction using motors, these systems are generally expensive and complicated.
Given these problems, there is a need for a control system that allows a physician to manipulate a minimally invasive medical device in any desired direction with a single hand. In addition, the system should be low cost and easy to manufacture.